Customer Substation Manual 08/05/02

Transcription

1 Customer Substation Manual

2 Table of Contents Section Page 2 of 85 Description 0 Preface General Information Required for the Review of New Customer Substations New Customer Substation Project Information Sheet We Energies Electrical System Information: Voltage and Fault Duties Typical Substation One Line Reference Sheet Schematic Index for a Typical Substation Metal Enclosed Gear with Two Line Feed Schematic Index for a Typical Substation Metal Enclosed Gear with Two Line Feed and a Bus Tie Switch 1 Electrical Requirements 100 Service Voltage 110 Short Circuit Duty 120 Disconnecting Means for Supply Conductors 130 Unprotected Bus 140 Service Overcurrent Protection Fuses Fuse Curves Fuse Mountings Circuit Breakers Relays Control Supply Battery Circuit Reclosers Operating Curves Reclosing Operation 150 Basic Impulse Insulation Level and Maximum Voltage Ratings BIL Levels and Maximum Continuous Operating Voltages for Substation Equipment 160 Surge Protection Surge Arresters Surge Arrester Classes 170 Transformer Connections and Taps Acceptable Transformer Connections for We Energies Systems T Connected Transformers Transformer Taps 180 Station Grounding General

3 Table of Contents Section Page 3 of 85 Description Indoor Substations Basement Level Substations Above Basement Level Substations Outdoor Substations Equipment and Structures Indoor and Outdoor Stations Substation Fence Fence Ground Interconnected With Station Ground Grid Fence Ground Isolated From Station Ground Grid Property Fence Outdoor Group Operated Switches 190 Protective Grounding General Grounding Provisions for Specific Equipment "Draw out" Circuit Breakers Stationary Mounted Circuit Breakers Oil and SF 6 Insulated Switches Power Fuses Grounding Cable Assemblies Grounding Facilities in Metal Enclosed Switchgear, Entrance Bay Power Fuse, Ground Attachment Detail /2" Ground Attachment Detail, 4 1/2" Depth and 7" Depth " Ground Bracket 195 Capacitors 197 Parallel Generation 2 Physical Requirements 200 Service Conductors General Overhead Service Conductors Underground Service Conductors Metal Enclosed or Metal Clad Switchgear Fed With Single Conductor Cable Direct Buried or Lead Jacketed Metal Enclosed or Metal Clad Switchgear Fed With Three Conductor Lead Jacketed Cable Outdoor Substation on Open Framework Fed With Direct Buried or Lead Jacketed Cable Special Equipment or Construction Size Requirements for Openings in Basement or Foundation Walls

4 Table of Contents Section Description Illustrations Cable Support, Drilling Detail (For Lead Jacketed Cable) Cable Support, Drilling Detail (For Direct Burial Cable) Cable Pulling Anchor Installation of Cable Pulling Anchor 210 Routes, Easements, and Space Requirements for Service Conductors 220 Metering General Required for Metering Above 600 Volts Only Metering Instrument Transformers Associated Metering Equipment Metering Cubicle Unit for Metal Clad or Metal Enclosed Switchgear Applications Metering Instrument Transformer Arrangement for Outdoor, Open Type Substations, 34,500 Volts and Below Street Light Transclosures Loss Compensated Metering Illustrations Typical Arrangements kV Metering Switchgear Unit kv Metering Switchgear Unit kv Metering Switchgear Unit kv Metering Switchgear Unit kv Metering Switchgear Unit Primary Metering Structure for Outdoor Open Type Substations 15kV and Below Primary Metering Structure for Outdoor Open Type Substations 3 Phase 4 Wire 25kV and Below Primary Metering Structure for Outdoor Open Type Substations 3 Phase 3 Wire and 3 Phase 4 Wire 26.4kV and 34.5kV Systems 230 Clearances and Spacing General Operating Space for Open Type Fuse Installations 240 Signs and Identification General Location Minimum Sign Requirements for Typical Customer Substations Signs for Outdoor Open Type Substations Page 4 of 85

5 Table of Contents Section Page 5 of 85 Description Signs for Indoor or Outdoor Substations Consisting of Metal Enclosed Switchgear With Loadbreak Switches and Fuses or With Draw Out Circuit Breakers 250 Enclosures, Fences, and Surfacing Outdoor Open Type Substations 260 Metal Enclosed and Metal Clad Service Entrance Switchgear General Doors Windows Detachable Panels Screen Doors Slide In Barriers Insulators Clearances Momentary Current Rating Protective Grounding Potheads and Other Cable Terminations Accessibility to Outdoor Switchgear 270 Indoor Substations General Transformer Vaults Vault Agreement 280 Interlock Systems General We Energies Required Interlocks for Specific Installations 3 Equipment Control 300 Introduction 310 Control Circuit Practices Control Circuit Relays Control Circuits Bus Fault Detection Instrument Transformer Connections Keyed Permissive Switches Miscellaneous Devices 320 Automatic Transfer Control for Switchgear and Circuit Breakers Position and Transfer Switch Operators and Breakers Switchgear Only Requirements

6 Table of Contents Section Description Circuit Breaker Only Requirements a Two Lines Serving a Common Load with Automatic Transfer b Two Lines Serving Separate Loads with Automatic Transfer Preferred/Alternate Source Selection Indicating Features Sensing 330 Switchgear or Circuit Breakers with Manual Transfer Two Lines Serving a Common Load with Manual Transfer Two Lines Serving Separate Loads with Manual Transfer Page 6 of 85

7 Preface ) General These requirements are applicable to all customer owned substation facilities at which We Energies supply lines are terminated ) The requirements contained herein are exclusively those of We Energies. However, additional requirements applicable to customer substations are set forth in the Wisconsin and Michigan State Electrical Code, IEEE Standards and other codes and ordinances. We Energies should be consulted only on matters relative to its specific requirements. Customers and Consultants are advised to communicate directly with appropriate code enforcement authorities for matters which pertain to requirements of the Wisconsin and Michigan State Electrical Codes, and other local codes or ordinances ) The We Energies general requirements which follow have been divided into specific sections as an aid to indexing the material covered for reference purposes. The division of the first two parts has been made on the basis of whether the listed characteristic primarily involves electrical or physical design criteria. These parts are Part 1 and Part 2, respectively. Control circuit requirements for service circuit breakers and electrically operated interrupter switches are specified in Part ) The general requirements contained herein relative to supply conductor terminations, grounding provisions, service disconnecting means, overcurrent protective devices, surge protection and metering facilities are those deemed necessary to insure the reliability of the We Energies system and the safety of We Energies personnel engaged in the We Energies normal operations as the supplying utility; therefore, all customer substation installations must comply and are reviewed and inspected accordingly ) We Energies, in its review and inspection, may specify additional requirements relative to the equipment and general design of the substation, as We Energies in an emergency situation may be requested to act as the Customer s contractor and operate the substation equipment ) The Customer shall obtain the acceptance of We Energies before making any additions or modifications to any existing customer owned substation. Page 7 of 85

8 Preface ) Information Required for the Review of New Customer Substations Prior to designing or ordering equipment for a customer substation, the Customer or their Contractor should request that the We Energies local office furnish Section We Energies Electrical System Information: Voltage and Fault Duty for the proposed installation (located near the front of this manual). The Customer shall provide the following: The street address for the proposed installation. The number, type and size of the transformer(s); The anticipated load (present and future); The requested service date; The preferred service location; The type of service (switchgear line up, rack in breaker style, overhead); And any other pertinent data. On completion of the substation design, the Customer shall submit quantity three (3) sets of engineering documents to the We Energies appropriate service center. This submittal shall occur prior to ordering any equipment. The prints will be reviewed for acceptance by a We Energies representative. The prints submitted for acceptance shall be details of the actual proposed installation, not typical drawings of a similar installation. These prints shall contain: Item Received Require Description 1 A one line diagram showing switches, fuses, transformers, surge arresters, interlock schemes, relaying and control schematics, etc. 2 A drawing showing the location and arrangement of the proposed installation with respect to adjacent facilities. 3 The type of equipment with reference to manufacturer and catalog number, electrical ratings, clearances between live parts and to ground, complete dimensions, etc. 4 A drawing showing the location and size of equipment foundations and ducts. 5 A drawing showing the location and provisions for metering equipment the locations for instrument transformers, the transformer rated meter socket, the cell phone enclosure, the associated conduit runs, etc. See Section A drawing showing the design of the electrical ground system and the provisions for protective grounding. See Section The provisions for warning signs and informational signs. See Section 240. Notes: Page 8 of 85

9 Preface ) New Customer Substation Project Information Sheet Today s Date Project Title Site Address City, State, Zip Code Quantity and Capacity of Transformers Anticipated Demand at Start Up Anticipated Demand at Ultimate Size Requested Start Up Date Preferred Service Location Customer Contact Phone Number E Mail Address Contract/Design Firm Contact Name Phone Number Address City, State, Zip Code E Mail Page 9 of 85

10 Preface ) We Energies Electrical System Information: Voltage and Fault Duty Date: Customer Name and Location: Prepared by: Line 1 Present Circuit Number System Description 3 Phase (Amps) Line Ground (Amps) Symmetrical Asymmetrical Symmetrical Asymmetrical Future Line 2 Present Circuit Number System Description 3 Phase Line Ground Symmetrical Asymmetrical Symmetrical Asymmetrical Future Line 1 OR Circuit Number System Description 3 Phase Line Ground Duty (Amps) X/R Duty (Amps) X/R Present Future Line 2 Present Circuit Number System Description 3 Phase Line Ground Duty (Amps) X/R Duty (Amps) X/R Future Page 10 of 85

11 Part 1: Electrical Requirements ) Schematic Index for a Typical Substation Metal Enclosed Gear with Single Line Feed Metal Enclosed Switchgear Assembly Service Voltage 110 Short Circuit Duty 120 Disconnecting Means for Supply Conductors 130 Unprotected Bus 140 Service Overcurrent Protection 150 Basic Impulse Insulation Level 160 Surge Protection 170 Transformer Connections and Taps Metering Bay Ground Bus We Energies owned incoming line and terminations Station Grounding 190 Protective Grounding 200 Service Conductors 210 Routes, Easements, Space Requirements for Service Conductors 220 Metering 230 Clearances and Spacing 240 Signs and Identification 260 Switchgear Page 11 of 85

12 Part 1: Electrical Requirements ) Schematic Index for a Typical Substation Metal Enclosed Gear with Two Line Feed Customer Switchgear Customer Feeder Bay (Future) Customer Feeder Bay Metering Bay 8 Incoming Line Bay (Reserve) Incoming Line Bay (Normal) Feeder Bay Disconnect (optional) Metering CTs PT Fuses Main Service Disconnects (must have slide-in isolating barriers) Customer Feeder (Future) Ground Bail Power Fuses Ground Bail Customer Feeder Voltage Transformers Ground Bail 6 Ground Bail Surge Arresters 6 We Energies Line #1 Point of Common Coupling Ground Bail Surge Arresters Ground Bail We EnergiesLine #2 6 Customer Owns We Energies Owns Station Grounding Requirements: See Section 180. All noncurent-carrying metallic parts which may become energized or statically charged (ie: switchgear enclosures) shall be connected to the ground grid in a minimum of two locations by conductors of adequate capacity and mechanical ruggedness. 1. Main Service Disconnect Section Unprotected Bus Section Fuses, Fuse Mountings Section Surge Protection Section Station Grounding Section Protective Grounding Section Service Conductors Section Metering Section Switchgear Section Interlock Systems Section Control Circuit Practices Section Automatic Transfer Control Section Manual Transfer Section 330 GENERAL: 14. Clearance and Spacing Section Signs and Identification Section 240 Page 12 of 85

13 Part 1: Electrical Requirements ) Schematic Index for a Typical Substation Metal Enclosed Gear with Two Line Feed and a Bus Tie Switch Customer Switchgear Main Service Disconnect (must have slide-in isolating barriers) Customer Feeder Bay Metering Bay 8 2 Incoming Line Bay Bus-Tie Bay Incoming Line Bay Metering Bay 8 Customer Feeder Bay Metering CTs Metering CTs Feeder Bay Disconnect (optional) Ground Bail Power Fuses Ground Bail PT Fuses Voltage Transformers Ground Bail Surge Arresters Bus-Tie Switch Customer Owns We Energies Owns Ground Bail Surge Arresters 1 6 PT Fuses 4 Voltage Transformers Ground Bail Power Fuses Ground Bail 3 Customer Feeder 7 6 Ground Bail Point of Common Coupling Ground Bail 6 Point of Common Coupling Ground Bail 6 Ground Bail Customer Feeder 7 We Energies Line #1 We Energies Line #2 5 Station Grounding Requirements: See Section 180. All noncurent-carrying metallic parts which may become energized or statically charged (ie: switchgear enclosures) shall be connected to the ground grid in a minimum of two locations by conductors of adequate capacity and mechanical ruggedness. 1. Main Service Disconnect Section Unprotected Bus Section Fuses, Fuse Mountings Section Surge Protection Section Station Grounding Section Protective Grounding Section Service Conductors Section Metering Section Interlock Systems Section Control Circuit Practices Section Automatic Transfer Control Section Manual Transfer Section 330 GENERAL: 14. Clearance and Spacing Section Signs and Identification Section Feeder Bay Disconnect (optional) Page 13 of 85

14 Part 1: Electrical Requirements 100) Service Voltages We Energies will specify the service voltage. We Energies may specify the use of dual voltage equipment in some areas of its service territory to accommodate planned conversion to a different service voltage. Page 14 of 85

15 Part 1: Electrical Requirements 110) Short Circuit Duty ) We Energies will provide the Customer the maximum three phase symmetrical fault current, system X/R ratio and the single phase to ground symmetrical fault current (or the maximum symmetrical and asymmetrical fault currents) for the proposed customer substation using the section New Customer Substation Project Information Sheet near the front of this manual ) Circuit protective device(s) shall have an interrupting rating sufficient for the system voltage and the current available at the terminals of the device ) Circuit protective devices will be restricted in size and timing to coordinate with existing We Energies source side devices ) Switching and disconnecting devices shall have a fault close rating sufficient for the current available at the terminals of the device ) All devices shall have a momentary withstand rating sufficient for the current available at the terminals of the device. Page 15 of 85

16 Part 1: Electrical Requirements 120) Disconnecting Means for Supply Conductors ) The Customer shall provide quantity one (1) disconnect device to isolate each set of We Energies supply circuits from the Customer substation equipment ) The disconnect device(s) shall be located at the nearest point of connection to the We Energies owned supply conductors ) The disconnect device(s) shall be readily accessible. The disconnect device(s) shall be located near a door or gate providing egress from the substation. Other substation equipment shall not be located between the door or gate and the operator of the disconnect device(s) ) Disconnect devices which are accepted by We Energies shall consist of one of the following types of equipment in a through d: a) A three phase group operated load interrupter switch. The device shall conform to the requirements of , and b) For single phase services, a single pole load interrupter switch. The device shall conform to the requirements of , and c) Non draw out type circuit breakers or circuit reclosers when associated with disconnect switch(es) located on the source side of the circuit breaker or recloser. The disconnect switches shall conform to the requirements of d) Draw out type circuit breakers ) The switch or disconnect shall provide a visible break of all circuit phases. The visible break shall be observable from the source side of the circuit breaker or recloser ) The switch shall be operated by a handle mechanism without exposing the operator to contact with live parts ) The operating handle shall have provisions for locking in the open and closed position. The customer shall lock the switch in the proper position, and provide a mechanism to allow We Energies personnel to operate the switch. This is typically accomplished by providing a key to the customer lock, or by providing a shackle which has an opening at either end (this allows the customer to install a lock at one end, and We Energies to install a lock at the other end). Page 16 of 85

17 Part 1: Electrical Requirements ) An insulator shall be installed in the operating pipe of any switch installed on a wood pole or metal structure. This insulator shall be rated to withstand the phase to ground voltages on the system it will ultimately be served from and shall be located at an elevation of 10 to 12 above the operating handle for the switch. Page 17 of 85

18 Part 1: Electrical Requirements 130) Unprotected Bus An unprotected main bus may only be installed when the following conditions are met: ) The design of the bus and all materials used in its construction shall be in accordance with We Energies requirements ) All taps from the bus shall be protected by We Energies accepted overcurrent devices ) Insulated cable is not allowed within the unprotected zone ) The circuit length of unprotected strain bus shall not exceed 25 feet without We Energies acceptance. Page 18 of 85

19 140.10) Fuses Fuse requirements are listed below. Customer Substation Manual Part 1: Electrical Requirements 140) Service Overcurrent Protection ) Fuse Curves The Customer shall provide We Energies information, including the manufacturer, type and family of time versus current curves for the proposed fuse type. We Energies will then specify the maximum fuse size that will be allowed at the particular substation location ) Fuse Mountings All outdoor fuse mountings installed in Customer Substations for service protection shall be of the disconnecting type and shall be removable using a hotstick ) Circuit Breakers Circuit breaker requirements are listed below ) Relays a) We Energies will specify the type and maximum setting of overcurrent relays. The Customer shall provide We Energies certified test reports verifying relay settings and calibration. b) The current transformers to which the overcurrent relays are connected shall be located on the supply side of the main circuit breaker ) Control Supply Battery The Customer shall provide, install and maintain a stationary storage battery of sufficient capacity to ensure tripping. Capacitor tripping schemes are not acceptable ) Circuit Reclosers Recloser requirements are listed below ) Operating Curves The Customer shall provide We Energies information including manufacturer, type and operating curves. We Energies will then specify the maximum trip current or control settings ) Recloser Operation The recloser must be equipped and set for single non reclosing operation. Automatic reclosing of Customer service protective devices is not permitted. Page 19 of 85

20 Part 1: Electrical Requirements 150) Basic Impulse Insulation Levels and Maximum Continuous Operating Voltages ) All high voltage equipment installed by the Customer on the line side of the service overcurrent protection devices shall have a BIL rating and rated maximum continuous operating voltage not less than that stated in ) All service overcurrent protection devices shall have BIL ratings and rated maximum continuous operating voltages not less than that stated in ) For installations without main service overcurrent protective devices, the main bus insulation systems and the overcurrent protective devices connected to the main bus shall have minimum BIL ratings and rated maximum continuous operating voltages not less than that stated in (next page). Page 20 of 85

21 Part 1: Electrical Requirements ) BIL Levels and Maximum Continuous Operating Voltages for Substation Equipment Nominal System Voltage (kv) Equipment BIL (kv) Notes Maximum Continuous Operating Voltage (kv) Maximum Phase to Ground Voltage During Faults (kv) Equipment Rated Maximum Continuous Operating Voltage Reduced BIL With Surge Protection (kv) 3.81Y/ Y/ Y/ Y/ Y/ Y/ Y/ Y/ Y/ Y/ or Y/ Y/ Notes: 1. By special permission only. Please contact the local We Energies office before designing for these voltages. 2. We Energies may accept the use of equipment with reduced BIL when the installation includes properly placed and appropriately rated surge arresters. We Energies shall be consulted in all cases where the installation of equipment with reduced BIL ratings is proposed. Page 21 of 85

22 Part 1: Electrical Requirements 160) Surge Protection ) The Customer shall install surge arresters on all circuit phases on the line side of the main service disconnect(s). These surge arresters shall be polymer body MOV arresters and require acceptance by We Energies ) If the Customer s distribution system is overhead and operates at the service voltage provided by We Energies (no transformation), the Customer shall install surge arresters on all circuit phases on the load side of the We Energies metering instrument transformers ) The application of the appropriate surge arrester class shall be determined based on the maximum fault duty quoted in section We Energies Electrical System Information: Voltage and Fault Duties located near the front of this manual. Please request this form for each installation location from the local We Energies representative. This information shall be used in conjunction with sections and (see the next page) to determine the appropriate arrester for the each site ) Arrester expulsion elements shall not be used inside metal enclosed or metal clad switchgear assemblies. Page 22 of 85

23 160.10) Surge Arresters Customer Substation Manual Part 1: Electrical Requirements SURGE ARRESTER NOMINAL CIRCUIT Duty Cycle MCOV VOLTAGE (V) Class Voltage Rating (kv) Rating (kv) Notes 3,810Y/2,200 DISTRIBUTION ,160Y/2,400 DISTRIBUTION ,320Y/4,800 DISTRIBUTION ,470/7,200 DISTRIBUTION ,200Y/7,620 DISTRIBUTION ,800Y/7,970 DISTRIBUTION ,200 INTERMEDIATE STATION ,800 INTERMEDIATE STATION ,940Y/14,400 DISTRIBUTION INTERMEDIATE ,400 INTERMEDIATE STATION ,500 INTERMEDIATE STATION ,500Y/19,920 INTERMEDIATE STATION , ,000 1 Note 1: By special permission only. Please contact the local We Energies office before designing for these voltages ) Surge Arrester Class PHASE TO GROUND SYMMETRICAL FAULT CLASS CURRENT (AMPERES) Distribution 10,000 or less Intermediate 20,000 or less Station >20,000 Page 23 of 85

24 Part 1: Electrical Requirements 170) Transformer Connections and Taps ) Acceptable Transformer Connections for We Energies Systems. Nominal Acceptable Transformer Connections System 3 Wire Secondary 4 Wire Secondary Row Voltage Primary Secondary Primary Secondary 1 *3,810/2,200V 4 Wire *4,160/2,400V 4 Wire *8,320/4,800V 4 Wire *12,470/7,200V 4 Wire 13,200/7,620V 4 Wire 13,800/7,970V 4 Wire 13,200V 3 Wire 26,400V 3 Wire Y GND Y 34,500V 3 Wire Y 2 13,800V 3 Wire See a. Y GND Y 3 24,940/14,400V 4 Wire 34,500/19,920V 4 Wire See b. GND Y Y GND Y GND Y Triplex Core Only Triplex Core Only 4 24,940/14,400V 4 Wire 34,500/19,920V 4 Wire Transformer must be 3000kVA or larger, or be protected as described in b.3. Y GND Y Y 5 24,940/14,400V 4 Wire 34,500/19,920V 4 Wire Transformer must be protected as described in b.3. 6 *69,000V 3 Wire GND Y Y GND Y GND Y 7 *138,000 V 3 Wire *By special permission only. Please contact the local We Energies office before designing for these systems. Table is continued on the next page. Page 24 of 85

25 Part 1: Electrical Requirements ) (continued) a) On the 13,800V 3 wire system, it is recommended that the Customer install three single phase transformers connected phase to phase. When the We Energies distribution system is converted to 24,940/14,400V 4 wire operation, the transformers may be reconnected in a grounded wye configuration (taking advantage of the high voltage taps as well). b) On the 24,940Y/14,400 volt and 34,500Y/19,920 volt systems, transformer installations shall have grounded wye primary winding connections, and three phase triplex core and coil design with grounded wye or ungrounded wye secondary winding connections. These restrictions are designed to avoid ferroresonant conditions and eliminate tank heating phenomena under all abnormal system operating conditions. b.1) Exception 1: When banking single phase transformers connected in a grounded wye to grounded wye configuration or grounded wye to ungrounded wye configuration. b.2) Exception 2: When the transformer rating is 3000kVA or more, transformer connections in Row 4 of are acceptable. b.3) Exception 3: When transformer(s) are protected with devices which sense the loss of source voltage by measuring voltage magnitude and phase angle, and will simultaneously disconnect all phases of the high voltage supply to the transformer(s) in the event of a loss of phase condition. Contact the local We Energies representative for acceptability before proceeding with this exception. b.4) Exception 4: Where a customer presently owns and operates a system and is adding transformation, the transformer connections on the existing equipment are acceptable for the new equipment (providing the connections are listed in Row 4 of ) ) T Connected Transformers T connected transformers shall not be utilized by the Customer at the We Energies supply voltage ) Transformer Taps Each transformer shall have five full capacity primary taps with one at nominal system voltage, and two taps at 2 1/2% above, and two taps at 2 1/2% below nominal system voltage. Customers installing transformers supplied by We Energies 13,800 volt and 26,400 volt distribution system shall contact We Energies for specific tap requirements prior to ordering the equipment. Page 25 of 85

26 Part 1: Electrical Requirements 180) Station Grounding ) General ) All substation grounding shall comply with the Wisconsin and Michigan State Electrical Codes and applicable local ordinances. The goal of a substation grounding system design is for the preservation of human life and the protection of equipment through the control of local potential ) This defines the minimum Company requirements for a grounding system; however it is not a design guide. The customer is responsible for the complete design. The following requirements are regarded by We Energies as minimum standards that must be met before We Energies personnel will enter and operate a customer substation, but do not in themselves guarantee that the design is adequate. A Company representative may add to the requirements and recommendations according to site conditions ) The size of the ground conductor shall be appropriate for the magnitude of the available fault current, the operating time of protective devices, and for sufficient mechanical ruggedness. The minimum conductor size for the ground grid and connections to the grid, ground rod and equipment cases shall be #1/0 copper ) Indoor Substations ) Basement Level Substations a) A 1/4" x 1 1/2" aluminum bar or equivalent copper bar shall be installed along all inside walls of the vault to form a closed loop. In damp areas copper bar shall be utilized. b) Five eighths (5/8) inch diameter copperweld ground rods shall be driven at all vault corners and approximately equally spaced along vault walls. Single 8 foot long rods at each rod location are adequate. Install as many ground rods as space permits, maintaining 6 foot typical separation between rods. Do not locate ground rods under doorways or in any other position where they will be hazardous to people walking in the vault. All ground rods are to be connected to the ground bus ) Above Basement Level a) A 1/4" x 1 1/2" aluminum bar or equivalent copper bar shall be installed along all inside walls to form a closed loop. In damp areas copper bar should be utilized. b) The ground bar referred to in a) shall be bonded to building steel in at least four places. The frames of all major equipment shall be bonded to building steel. Page 26 of 85

27 180.30) Outdoor Substations Customer Substation Manual Part 1: Electrical Requirements ) A grid is required under the entire area substation, consisting of bare stranded copper cable buried 18 to 24 inches below the soil rough grade. The grid conductors shall be placed 15 feet apart or less depending on soil resistivity. In areas in which We Energies suspects high resistivity soil, such a quarry, step and touch potential calculations shall be provided with the approval drawings per IEEE 80. A 4 ft by 2 ft grounding mesh is an acceptable supplement to the grid in the absence of these calculations. When required, the supplemental mesh must be installed on top of the rough grade, just under the crushed stone layer. Within the grid, cables connecting ground rods should be laid in parallel lines and uniformly spaced. They should be located, where practical, along rows of structures or equipment to facilitate the making of ground connections. These rows are to be interconnected at various points including the peripheral cable to form a grid. Interconnecting conductor size should not be less than that of the ground bus or grid ) Five eighths (5/8) inch diameter copperweld ground rods shall be driven to a depth of 8 feet or more at all ground grid corners and approximately equally spaced along the grid perimeter. All ground rods are to be connected to the grid conductors ) A layer of gravel or crushed stone (minimum 6 inches in depth) shall be placed over the entire grid to establish the finished grade ) A buried ground conductor shall encircle all switchgear and transformers within 18 inches of the edge of the equipment enclosure, at a burial depth of at least 18 inches but less than 24 inches ) Equipment and Structures Indoor and Outdoor Stations All noncurrent carrying metallic parts which might accidentally become energized or statically charged (such as switchgear enclosures, metal structures, building steel, transformer tanks, metal railings, housings, and guards, oil circuit breaker tanks and circuit neutrals) shall be connected to the grid or ground bus in a minimum of two locations by conductors of adequate capacity and mechanical ruggedness. The grid or ground bus should also be connected to any metallic water pipe, metallic drain or sewer pipe located in the station area. Connection shall be made at two points on the pipe at least 20 feet apart and shall consist of a conductor not less than the size of the ground bus ) Substation Fences The metal fence surrounding an outdoor open type substation shall be grounded in accordance with all applicable electrical codes. Of primary concern in the design of a fence grounding system is the reduction of potentials which could prove hazardous to persons within the fence enclosure or approaching from outside. Page 27 of 85

28 Part 1: Electrical Requirements ) Fence Ground Interconnected With Station Ground Grid a) Consideration shall be given to interconnecting the station ground grid with the fence grounds at frequent intervals. b) The station ground grid shall be extended 2 feet beyond the substation fence. All corner and gate posts, as well as fence posts shall be connected to the grid. c) All metallic fence parts that might accidentally become energized or statically charged must be metallically connected together. At each entrance gate a buried ground conductor loop connected at each end to the perimeter fence ground conductor shall be placed so as to form a rectangle which encompasses an area extending at least 18 inches beyond the gate swing ) Fence Ground Isolated From Station Ground Grid a) If the Customer elects to isolate the fence ground system from the station ground grid, a potential difference may be present between the station equipment and the fence during fault conditions. b) Under this condition, a minimum separation of 6 feet shall be maintained between the fence and the nearest station ground conductor, grounded equipment, or structure ) Property Fence ) These requirements are in addition to grounding requirements for substation fences (Item F above). Where a metallic property fence is attached to, or passes within 6 feet of a substation fence, it becomes an extension of the substation fence and must be treated accordingly ) Metal property fences installed on the Customer s property shall be grounded to ground rods installed one foot inside the fence at corner posts, gate posts, and at posts on each side of an overhead transmission or distribution line crossing. No connection with the substation ground system is necessary where a minimum separation of 6 feet is maintained between the substation fence and metallic property fence. A buried conductor connecting gateposts is recommended. Fence isolation sections may be utilized to electrically isolate extended sections of property fence from the substation. Page 28 of 85

29 Part 1: Electrical Requirements ) Outdoor Group Operated Switches In outdoor stations utilizing load break switches mounted on wood poles or metal structure, a three foot by four foot metallic grating shall be installed on the surface where a person stands when operating the switch. This section of grating shall be connected to the ground grid and the switch operating linkage as close as is practical to the handle. A minimum of #1/0 Cu conductor shall be used for this connection. Page 29 of 85

30 Part 1: Electrical Requirements 190) Protective Grounding ) General The following requirements shall be used as a guide for determining when and where provisions are needed for the attachment of temporary grounds ) Protection of personnel and property is the primary reason for the attachment of temporary grounds. Hazardous potential differences can exist between apparently de energized electrical conductors or current carrying parts of equipment and some other point. These potential differences may exist if the conductor is either accidentally energized or becomes charged because of its proximity to other energized conductors. Proper grounding and bonding will effectively eliminate such hazards ) Wisconsin and Michigan's State Electrical Codes and company operating practices dictate that de energized conductors and other current carrying equipment parts shall be grounded during the time construction or maintenance work is being done on them. Such grounding is generally accomplished by connecting a temporary ground cable assembly between the conductor and some grounded point. Under certain conditions, special provisions for the attachment to equipment such as grounding switches may be required where the use of individual ground cables would be impractical or hazardous ) The customer shall install "adequate grounding provisions" in each customer substation ) The Company requirements which follow do not cover every situation where grounds might be needed. However, by using the specific requirements included herein as a guide and with an understanding of the hazards involved if grounds are not applied, "adequate provisions" can be made at locations not specifically covered. Each potential source shall be isolated by a visible open from the work area. In addition, safety grounds shall be installed between the visible open and the work area. This document is intended to describe the equipment to meet those criteria ) In some substations grounds can be attached directly to the equipment or conductors. However, because of the limitation in ground clamp range and physical clearances required for safe installation of such clamps, special provisions (ground attachment details) must be made in certain cases for the attachment of ground cable assemblies. Such special provisions (ground attachment details) are also required for bus conductors of special shapes, such as rectangular bar, angle, channel, etc., and at certain locations to make the application of grounds more convenient ) All grounding provisions installed by the customer shall be located so as to render them accessible for safe and convenient application of ground cable assemblies. Page 30 of 85

31 Part 1: Electrical Requirements ) The Customer shall provide and install Company approved grounding provisions for each incoming line (overhead service conductor or underground service cable). Refer to drawing ) Unless otherwise specified or permitted, such grounding provisions shall consist of a ground attachment detail permanently attached to each incoming line conductor at a conveniently accessible point on the line side of the Customer's main disconnect and ground bracket(s) located within the incoming line section and permanently connected to the station ground bus ) Refer to drawings , , and for material specifications on the ground details and brackets ) Grounding Provisions for Specific Equipment Applications for which basic requirements for line grounding provisions differ from those indicated above are outlined in the following paragraphs: ) "Draw out" Circuit Breakers a) When "draw out" circuit breakers are used for service switching and overcurrent protection at customer substations, the customer shall provide a three pole ground/test device. b) The ground test device is racked into a compartment in place of the circuit breaker, providing access to the completely insulated switchgear bus conductors for line grounding, bus grounding, low voltage phase identification, and live line phasing. Ground cable assemblies and ground brackets are used to complete the connections between the line or bus conductors and the substation ground system. An additional ground/test device may be required in some configurations ) Stationary Mounted Circuit Breakers In all customer substations using stationary mounted circuit breakers for service protection, the Customer shall install ground attachment facilities on both line and load side of the breaker. These facilities can generally be installed on the breaker bushings or isolation disconnect switches. Ground brackets connected to the station ground bus are required for each set of attachment facilities. Page 31 of 85

32 ) Oil and SF 6 Insulated Switches Customer Substation Manual Part 1: Electrical Requirements a) Oil switches utilized as the customers service disconnect shall have incoming cable terminations in air filled compartments. Isolating means shall be provided between the cable terminations and the switch tank bushings. The customer shall provide and install a ground attachment detail at each cable termination. Ground brackets connected to the station ground bus shall be provided for each set of ground attachment facilities b) An alternate method may be employed through the use of insulated connectors and bushings. These must have the capability for phase testing, Hi Potential and fault locate testing, testing for energized/de energized condition, providing a visible circuit open point, and line grounding ) Power Fuses The customer equipment shall accommodate grounding on both supply and load side of power fuses which cannot be replaced by means of a switch stick (due to weight, lack of accessibility, or the style of the fuse mount). These accommodations shall consist of ground attachment details installed on the supply side and load side terminals of each fuse mounting. Further, the fuse bay shall contain ground brackets totaling a minimum of 18". The ground brackets shall be connected to the station ground bus. These details are to accommodate safe and expeditious fuse replacement. Exception: Supply side grounding details are not required if the equipment has slide in isolating barriers for the fuses (or switch if located in the same compartment) ) Grounding Cable Assemblies ) The customer shall provide all necessary grounding cables ) Ground cable assemblies shall be rated for their intended application. In cases where the Company's standard ground cable assemblies are of inadequate length, special clamping devices are required, the substation is not directly accessible from outside, or other unique circumstances prevail, the Customer shall provide special ground cable assemblies to be used only at the applicable station ) Where additional grounding provisions are installed beyond those specifically required by the Company, and/or where the Company required grounding provisions also include facilities for station bus or equipment grounding, as in the case of ground test devices (see ), the Customer shall provide at least one set consisting of three ground cable assemblies. Such cable assemblies shall be of adequate size and sufficient length as required for the specific application. Page 32 of 85

33 Part 1: Electrical Requirements ) When required to provide ground cable assemblies, the Customer shall also provide suitable storage facilities for such devices. When not in use, ground cable assemblies should be stored appropriately for accessibility and protection from the elements. Page 33 of 85

34 Part 1: Electrical Requirements Grounding Facilities in Metal Enclosed Switchgear Service Conductor Entrance Bays Page 34 of 85

35 Part 1: Electrical Requirements Power Fuse Ground Attachment Detail Page 35 of 85

36 Part 1: Electrical Requirements /2" Ground Attachment Detail, 4 1/2" Depth and 7" Depth Page 36 of 85

37 Part 1: Electrical Requirements " Ground Bracket Page 37 of 85

38 Part 2: Physical Requirements 195) Capacitors ) The installation of shunt capacitors for power factor correction in customer substations can have undesirable effects upon We Energies supply and customers distribution system. Care should be taken when specifying capacitors. During off peak conditions, an excessive voltage rise or a leading power factor can occur. If the capacitors are switched, a voltage dip, light flicker, high frequency ringing, etc. are possible. Switching can also result in over and under voltages which can cause variable speed drives to shut down. In some applications, capacitors may provide a low impedance path for harmonics which may result in operation of protective devices. Harmonics may contribute to a "loss of life" for capacitors. It is suggested that customers have some knowledge of their harmonic levels, or pursue a harmonic analysis prior to specifying capacitors. No general limitations on capacitor size can be made, since the factors which produce these effects vary with the location of the customer s substation, characteristics of the customers load, etc ) The customer shall obtain approval from We Energies for the installation of shunt capacitors. We Energies may place restrictions on the use of these capacitors with respect to voltage regulation, telephone interference or other factors. Capacitors operating at lower voltages which are switched with individual loads are exempt from any restrictions ) Shunt capacitors connected to three phase, three wire systems are not grounded to: avoid possible interference with telephone equipment, obtain better compensation for unbalanced voltages. It may be necessary, however, to ground shunt capacitors installed at certain locations on the three phase, three wire systems to obtain proper coordination of protective devices ) Shunt capacitors installed on 13,200 volt, 13,800 volt, 26,400 volt, 34,500 volt, 69,000 volt, and 138,000 volt three phase, three wire systems shall be wye connected for ungrounded operation. Page 38 of 85

39 Part 2: Physical Requirements 197) Parallel Generation The Customer shall contact We Energies for specific requirements concerning power quality, relaying, liability and safety. Page 39 of 85

40 Part 2: Physical Requirements 200) Service Conductors ) General ) For the purpose of this discussion, service conductors are the electrical supply line(s), overhead or underground, which are installed, owned, and maintained by the Company between its distribution system and the Customer s substation. These conductors are installed, owned, and maintained by the Company even though in some cases the Customer may be required to make a financial contribution toward their cost ) The following paragraphs are intended to provide the Customer with general information relative to the Company s requirements for termination of service conductors and to designate a point at which division of ownership occurs. The Company will provide additional supplementary details as required, especially where underground services are involved ) Overhead Service Conductors ) Overhead service conductors are terminated on a deadend structure provided by the Customer. The Company will provide the following data for each overhead service to a substation to assist the Customer in the design of an appropriate deadend structure. a) Approximate heavy loaded tension for each conductor associated with the service. b) Required conductor spacing and configuration at point of attachment. c) Minimum attachment height necessary to provide adequate clearance for service conductors ) Customer shall provide and install a deadend structure of adequate size and structural strength consistent with data furnished by the Company ) Where such deadend structures are constructed of wood, the Customer need not provide additional termination details. The Company will drill the necessary holes and furnish and install all required attachment hardware ) Where steel deadend structures are employed, the Customer shall furnish and install suitable attachment provisions ) Underground Service Conductors The Company will generally provide, install and terminate the incoming service lateral cable(s) when the supply to a Customer substation is underground. The following paragraphs outline specific Company requirements for representative installations: Page 40 of 85

41 Part 2: Physical Requirements ) Cubicle Type Substations Consisting of Metal Clad or Metal Enclosed Switchgear Supplied Via Single Conductor Direct Burial Service Lateral Cable or Single Conductor Lead Jacketed Cables The Customer shall furnish and install the following facilities for entry and termination of underground service lateral(s): a) Terminal pad with NEMA standard two hole drilling on which service lateral cables are to be terminated. The Company will connect service lateral cables to Customer's terminal pad with a NEMA standard two hole cable lug. Such terminal pads shall be located no less than 25" for 26,400 Volts and below and 30" for 34,500 Volts above terminal compartment floor or bottom of cable trench (where present). b) Where service lateral cables are to be terminated six feet or more above the bottom of the cable trench or cubicle compartment floor, a structural member shall be provided, securely fastened to the terminal compartment walls complete with appropriate drilling to receive service lateral cable clamps. Cable clamp supporting member shall be located three feet minimum and four feet maximum below the center line of cable termination pads. Refer to to determine required cable clamp drilling. c) Station ground bus to be extended to the vicinity of cable termination. We Energies will furnish and install the materials necessary for bonding the service lateral concentric strands or lead sheath to the station ground bus. d) Access to the service lateral termination compartment(s) shall be by hinged door(s) at the front or rear of the switchgear. We Energies will provide the necessary padlock(s). e) Working space in front of cable termination shall be clear of all obstructions. This working space is for the installation and maintenance of the de energized termination. Equipment mounted in front of the termination point shall be removable to permit proper installation of service lateral cables. f) Service lateral conduit. Conduit shall enter switchgear from the bottom. Top and side entrances are not permitted. g) Indoor Substation Application Only g.1) Cable pulling anchors (see and ), installed at the locations specified by the Company. g.2) Customer substations located below grade shall be provided with a 12 inch wide by 6 inch (minimum) deep cable trench in the floor as specified by the Company. Depth of Page 41 of 85